The goal is to provide Debian and Ubuntu nightly packages ready to be installed with minimal impact on the distribution.
Packages are available for amd64 and i386 (except for recent Ubuntu) and for both the stable, old-stable and development branches (currently 10, 11 and 12).

Packages are built using stage2 and extremely similar to the one shipping in Debian & Ubuntu.

The packages provide LLVM + Clang + compiler-rt + polly + LLDB + LLD + libFuzzer + libc++ + libc++abi + openmp

Nov 01th 2020 - Ubuntu Groovy (20.10) & Hirsute (21.04) support
Nov 01th 2020 - Ubuntu Eoan removed (EOL)
Jul 15th 2020 - Snapshot becomes 12, branch 11 created
Apr 14th 2020 - Ubuntu Disco removed (EOL)
Apr 06th 2020 - Ubuntu Focal (20.04) support
Jan 23th 2020 - Snapshot becomes 11, branch 10 created
Jan 19th 2020 - Ubuntu Cosmic removed (EOL)
Oct 30th 2019 - Ubuntu Eoan (19.10) support
Aug 20th 2019 - Ubuntu Trusty removed (EOL)
Aug 01th 2019 - Snapshot becomes 10, branch 9 created
Apr 07th 2019 - Debian Buster (10) added
Apr 06th 2019 - Debian Jessie (oldstable) no longer maintained
Jan 19th 2019 - Branch 8 created
Jan 19th 2019 - Ubuntu Disco (19.04) support
Jan 19th 2019 - Artful jobs disabled (but packages still available)

For convenience there is an automatic installation script available that installs LLVM for you.
To install the latest stable version:

bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)"

To install a specific version of LLVM:

wget https://apt.llvm.org/llvm.sh
chmod +x llvm.sh
sudo ./llvm.sh <version number>

Stretch (Debian 9 - oldstable) - Last update : Mon, 09 Nov 2020 16:28:35 UTC / Revision: 20201108102911+2af0edefd6d

deb http://apt.llvm.org/stretch/ llvm-toolchain-stretch main
deb-src http://apt.llvm.org/stretch/ llvm-toolchain-stretch main
# 10 
deb http://apt.llvm.org/stretch/ llvm-toolchain-stretch-10 main
deb-src http://apt.llvm.org/stretch/ llvm-toolchain-stretch-10 main
# 11 
deb http://apt.llvm.org/stretch/ llvm-toolchain-stretch-11 main
deb-src http://apt.llvm.org/stretch/ llvm-toolchain-stretch-11 main

Buster (Debian 10 - stable) - Last update : Mon, 09 Nov 2020 17:42:02 UTC / Revision: 20201109115112+5c987212b7b

deb http://apt.llvm.org/buster/ llvm-toolchain-buster main
deb-src http://apt.llvm.org/buster/ llvm-toolchain-buster main
# 10 
deb http://apt.llvm.org/buster/ llvm-toolchain-buster-10 main
deb-src http://apt.llvm.org/buster/ llvm-toolchain-buster-10 main
# 11 
deb http://apt.llvm.org/buster/ llvm-toolchain-buster-11 main
deb-src http://apt.llvm.org/buster/ llvm-toolchain-buster-11 main

sid (unstable) - Last update : Thu, 05 Nov 2020 13:07:15 UTC / Revision: 20201104111113+694c16a8238

deb http://apt.llvm.org/unstable/ llvm-toolchain main
deb-src http://apt.llvm.org/unstable/ llvm-toolchain main
# 10 
deb http://apt.llvm.org/unstable/ llvm-toolchain-10 main
deb-src http://apt.llvm.org/unstable/ llvm-toolchain-10 main
# 11 
deb http://apt.llvm.org/unstable/ llvm-toolchain-11 main
deb-src http://apt.llvm.org/unstable/ llvm-toolchain-11 main

Precise, Quantal, Raring, Saucy, Utopic, Artful, Cosmic, Eoan and Trusty are no longer supported by Ubuntu. Repo remains available

Xenial LTS (16.04) - Last update : Mon, 09 Nov 2020 06:46:51 UTC / Revision: 20201109020810+2af0edefd6d

deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial main
deb-src http://apt.llvm.org/xenial/ llvm-toolchain-xenial main
# 10
deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-10 main
deb-src http://apt.llvm.org/xenial/ llvm-toolchain-xenial-10 main
# 11
deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-11 main
deb-src http://apt.llvm.org/xenial/ llvm-toolchain-xenial-11 main

Bionic LTS (18.04) - Last update : Mon, 09 Nov 2020 14:01:54 UTC / Revision: 20201109091413+053110b22aa

# i386 not available
deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic main
deb-src http://apt.llvm.org/bionic/ llvm-toolchain-bionic main
# 10
deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-10 main
deb-src http://apt.llvm.org/bionic/ llvm-toolchain-bionic-10 main
# 11
deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-11 main
deb-src http://apt.llvm.org/bionic/ llvm-toolchain-bionic-11 main

Focal (20.04) LTS - Last update : Sun, 08 Nov 2020 22:08:36 UTC / Revision: 20201108052612+00808e321c7

# i386 not available
deb http://apt.llvm.org/focal/ llvm-toolchain-focal main
deb-src http://apt.llvm.org/focal/ llvm-toolchain-focal main
# 10
deb http://apt.llvm.org/focal/ llvm-toolchain-focal-10 main
deb-src http://apt.llvm.org/focal/ llvm-toolchain-focal-10 main
# 11
deb http://apt.llvm.org/focal/ llvm-toolchain-focal-11 main
deb-src http://apt.llvm.org/focal/ llvm-toolchain-focal-11 main

Groovy (20.10) - Last update : Mon, 09 Nov 2020 14:15:07 UTC / Revision: 20201109113612+a7a447be0fa

# i386 not available
deb http://apt.llvm.org/groovy/ llvm-toolchain-groovy main
deb-src http://apt.llvm.org/groovy/ llvm-toolchain-groovy main
# 10
deb http://apt.llvm.org/groovy/ llvm-toolchain-groovy-10 main
deb-src http://apt.llvm.org/groovy/ llvm-toolchain-groovy-10 main
# 11
deb http://apt.llvm.org/groovy/ llvm-toolchain-groovy-11 main
deb-src http://apt.llvm.org/groovy/ llvm-toolchain-groovy-11 main

Hirsute (21.04) - Last update : Mon, 09 Nov 2020 14:37:09 UTC / Revision: 20201108083512+4dde325004d

# i386 not available
deb http://apt.llvm.org/hirsute/ llvm-toolchain-hirsute main
deb-src http://apt.llvm.org/hirsute/ llvm-toolchain-hirsute main
# 10
deb http://apt.llvm.org/hirsute/ llvm-toolchain-hirsute-10 main
deb-src http://apt.llvm.org/hirsute/ llvm-toolchain-hirsute-10 main
# 11
deb http://apt.llvm.org/hirsute/ llvm-toolchain-hirsute-11 main
deb-src http://apt.llvm.org/hirsute/ llvm-toolchain-hirsute-11 main

To make sure always the most recent versions of the packages are installed, we are providing some default packages.
To install all of them (currently version 12):

apt-get install clang-format clang-tidy clang-tools clang clangd libc++-dev libc++1 libc++abi-dev libc++abi1 libclang-dev libclang1 liblldb-dev libllvm-ocaml-dev libomp-dev libomp5 lld lldb llvm-dev llvm-runtime llvm python-clang

To retrieve the archive signature:

wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key|sudo apt-key add -
# Fingerprint: 6084 F3CF 814B 57C1 CF12 EFD5 15CF 4D18 AF4F 7421

To install just clang, lld and lldb (10 release):

apt-get install clang-10 lldb-10 lld-10

To install all key packages:

# LLVM
apt-get install libllvm-10-ocaml-dev libllvm10 llvm-10 llvm-10-dev llvm-10-doc llvm-10-examples llvm-10-runtime
# Clang and co
apt-get install clang-10 clang-tools-10 clang-10-doc libclang-common-10-dev libclang-10-dev libclang1-10 clang-format-10 python-clang-10 clangd-10
# libfuzzer
apt-get install libfuzzer-10-dev
# lldb
apt-get install lldb-10
# lld (linker)
apt-get install lld-10
# libc++
apt-get install libc++-10-dev libc++abi-10-dev
# OpenMP
apt-get install libomp-10-dev

To retrieve the archive signature:

wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key|sudo apt-key add -
# Fingerprint: 6084 F3CF 814B 57C1 CF12 EFD5 15CF 4D18 AF4F 7421

To install just clang, lld and lldb (11 release):

apt-get install clang-11 lldb-11 lld-11

To install all key packages:

# LLVM
apt-get install libllvm-11-ocaml-dev libllvm11 llvm-11 llvm-11-dev llvm-11-doc llvm-11-examples llvm-11-runtime
# Clang and co
apt-get install clang-11 clang-tools-11 clang-11-doc libclang-common-11-dev libclang-11-dev libclang1-11 clang-format-11 python-clang-11 clangd-11
# libfuzzer
apt-get install libfuzzer-11-dev
# lldb
apt-get install lldb-11
# lld (linker)
apt-get install lld-11
# libc++
apt-get install libc++-11-dev libc++abi-11-dev
# OpenMP
apt-get install libomp-11-dev

To retrieve the archive signature:

wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key|sudo apt-key add -
# Fingerprint: 6084 F3CF 814B 57C1 CF12 EFD5 15CF 4D18 AF4F 7421

We also provide meta packages to move from a major version to the other.
For example, to automatically upgrade to the current major:

apt-get install clang lld # clang-12 lld-12 can be added to automatically install the most recent version of the package.

To install just clang, lld and lldb (12 release):

apt-get install clang-12 lldb-12 lld-12

To install all key packages:

# LLVM
apt-get install libllvm-12-ocaml-dev libllvm12 llvm-12 llvm-12-dev llvm-12-doc llvm-12-examples llvm-12-runtime
# Clang and co
apt-get install clang-12 clang-tools-12 clang-12-doc libclang-common-12-dev libclang-12-dev libclang1-12 clang-format-12 python-clang-12 clangd-12
# libfuzzer
apt-get install libfuzzer-12-dev
# lldb
apt-get install lldb-12
# lld (linker)
apt-get install lld-12
# libc++
apt-get install libc++-12-dev libc++abi-12-dev
# OpenMP
apt-get install libomp-12-dev

Packages are rebuilt against the trunk of the various LLVM projects.
They are rebuild through a Jenkins instance:
https://llvm-jenkins.debian.net

Bugs

Bugs should be reported on the LLVM bug tracker (deb packages).

Workflow

Twice a day, each jenkins job will checkout the debian/ directory necessary to build the packages. The repository is available on the Debian hosting infrastructure: https://salsa.debian.org/pkg-llvm-team/llvm-toolchain/. In the llvm-toolchain-*-source, the following tasks will be performed:

• upstream sources will be checkout
• tarballs will be created. They are named:
  • llvm-toolchain_X.Y~svn123456.orig-lldb.tar.bz2
  • llvm-toolchain_X.Y~svn123456.orig-compiler-rt.tar.bz2
  • llvm-toolchain_X.Y~svn123456.orig.tar.bz2
  • llvm-toolchain_X.Y~svn123456.orig-clang.tar.bz2
  • llvm-toolchain_X.Y~svn123456.orig-polly.tar.bz2
  • ...
• Debian .dsc package description is created
• Start the jenkins job llvm-toolchain-X-binary

Then, the job llvm-toolchain-X-binary will:

• Create a chroot using cowbuilder or update it is already existing
• Build all the packages
• Launch lintian, the Debian static analyzer
• Publish the result on the LLVM repository

Note that a few patches are applied over the LLVM tarballs (and should be merged upstream at some point).

With the Jenkins instance, several reports are produced:

• Scan build report
• Code coverage
• Coverity reports

Building LLVM packages from source is documented in a dedicated page.